[Diy_efi] could i have multiple bad injectors?

Tue Jan 21 17:59:24 GMT 2003

mike,

i haven't ever ran water or methanol or alcohol through the injectors. the 
coils have not ever been engergized under my ownership as well, as i haven't 
gotten to that stage yet. they are low impedeance, and the AIC 3 is designed 
to control either after setting which type you have, but again, i haven't 
ever had it plugged in as of yet, so the coils could not have been over 
driven either, but a good suggestion none the less.
it has absolutely no electrical connection, very good assumption, and the 
rail pressure is 37 (with no vacuum signal) verified by my electrical fuel 
pressure gauge and my mechanical one.
i will examine them tonight with a magnifying glass to see if i can visually 
see damage, one other thing to note is that they don't leak immediately, it 
takes a couple of seconds for the fuel to push past the pintel? is that 
consistent with a bent or damaged pintel?

thanks for the info mike

-j

From: Mike <erazmus at iinet.net.au>
>Reply-To: List for general do-it-yourself EFI talk <diy_efi at diy-efi.org>
>To: List for general do-it-yourself EFI talk <diy_efi at diy-efi.org>
>Subject: re: [Diy_efi] could i have multiple bad injectors?
>Date: Tue, 21 Jan 2003 23:50:33
>
>A good magnifying glass helps to look at the pintle, though
>you have to pull off the plastic covers (well mine had some),
>also have you run any other fuel through them ?
>
>I hear rumours that running water for even a short time will
>produce enough corrosion so the metal to metal seal of the injector
>is compromised. Also if you have run alcohol or methanol in
>a petrol only injector then there could be some corrosion after
>a while, also is your fuel really clean and free of particles,
>these might also cause the pintle to not close properly,
>
>Other thing is - have you over-driven the coils, say put low
>impedance injectors on and left driven hard for too long,
>ie. Not pulsed - this can overheat the coil and the spring
>and effectively 'operation outside specs'...
>
>Also I take it you are testing on your system with absolutely
>no electrical connection, not just assumption its not driven,
>ie. Connector actually removed, so if you see a dribble from
>the pintle when pressurised, dont bother with them, toss em
>out...
>
>Then if your rail pressure is really OK and not out by say a
>factor of 10 (dont laugh - I've seen that one on a pressbrake!),
>then it does indicate injectors are stuffed - if you got them
>new then take em back on warranty unless you've run an ionic
>fuel through them for any length of time - or water :(
>
>rgds
>
>mike
>
>
>
>At 10:12 AM 21/1/2003 -0500, you wrote:
> >thank you for the replies, just to clarify
> >
> >the injectors are not receiving any sort of electrical signal, once they
> >prove to function properly, they will be hooked up to an AIC 3, but right
> >now, it is nothing.
> >since the injector is the only path for the fuel to get from the rail to 
>the
> >manifold, they have to be the source of leakage, but i am not sure as to
> >why. mike has mentioned that they could have had the pintel bent, which 
>at
> >least is feasible, but i was careful to set them down with the ends up in
> >the air, and not resting on anything. i will probably try a test with a
> >bucket full of fuel and a pump to see if i can simulate conditions.
> >
> >the fuel pressure is 35 or 37 pounds for base, they have never seen boost
> >and are leaking at the base pressure, and they have not received an
> >electrical signal as of yet.
> >
> >is there a way to to examine the injectors to see if the pintel is
> >physically damaged, does it bend or kink open and will i be able to 
>visually
> >inspect and see that?
> >
> >thanks again for the replies
> >
> >-j
> >
> >
> >
> >
> >
> >
> >
> >=====================================================================
> >
> >Some ECUs will sort of crack open the injectors if the driver
> >circuit loses a signal ground. Check your grounding all over
> >(engine to chassis, chassis to powertrain, chassis to ECU, and
> >while you're at it clean up the straps to shiny and coat with
> >thick grease after assembly). Let us know how you get on.
> >
> >Cheers,
> >Rod
> >
> >
> >=====================================================================
> >
> >
> >I changed all my bosch injectors about a year ago and during
> >the process I noticed its very easy to bump/graze the small
> >pintle at the end of the injector!
> >
> >So if there is fuel pressure and no signal and they leak then its
> >logical to conclude they have received physical damage *or* your
> >fuel pressure is way too high for the injectors...
> >
> >rgds
> >
> >mike
> >
> >
> >=====================================================================
> >
> >
> >
> >Those should actually be Nippon Denso 450cc injectors and they are very
> >reliable.  I really doubt it is bad injectors.  You just changed to 
>staged
> >injection, so I would look into that.  It sounds like they are being 
>fired
> >when they shouldn't be.  Usually when those injectors go bad they will 
>not
> >fire at all.  I have had one go bad in 9 years having Talons.
> >
> >JET
> >92 Talon AWD
> >
> >
> >=====================================================================
> >
> >
> >----- Original Message -----
> >From: "Toyota Supra" <turbosupramk3 at hotmail.com>
> >To: <diy_efi at diy-efi.org>
> >Sent: Monday, January 20, 2003 9:29 PM
> >Subject: [Diy_efi] could i have multiple bad injectors?
> >
> >
> >>as a background, i have just installed staged injection on my 6 
>cylinder,
> >as
> >>it was being tried out, the smell of fuel was prevelant without the car
> >>running. after searching for leaks, i could see fuel leaking in between
> >the
> >>upper and lower intake manifolds, because it was leaking past the 
>injector
> >>and into the manifold, then puddling and seeping past the gasket
> >>
> >>... now, how could i have more than 1 injector do this? the odds are
> >pretty
> >>astronomical i would think? the secondaries are bosch style 440cc
> >injectors
> >>out of a talon (1 and a half sets) and the car ran great before removing
> >the
> >>very injectors i am trying to use, and upgrading to larger ones.
> >>
> >>so to summarize, i have 2 or 3 failing eclipse/talon/laser injectors, 
>base
> >>pressure is only at 37 pounds, and there is no electrical signal going 
>to
> >>the injectors to open them. i can't see the injectors having a normally
> >open
> >>coil, or everytime the car ignition was on, and the fuel system was
> >primed,
> >>it would flood before the ecu started to oscillate the injectors and
> >>signalling them to close
> >>
> >>sorry for the long post, i just can't figure out what is going on here,
> >any
> >>and all info or theories would be appreciated. thanks
> >>
> >>-j
> >>
> >>
> >
> >
> >
> >
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